Check for missing argument or incorrect argument data type in call to function 'expand'

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Priyanshu 2023-7-16

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1996638-check-for-missing-argument-or-incorrect-argument-data-type-in-call-to-function-expand

评论： Priyanshu 2023-7-17

After using sym2poly to get the coefficients of a polynomial, I get the following : B = 1.0e+07 * 0.0000 0.0003 0.0103 2.5110 2.6503 -0.0500 Then I am trying to multiply the 1.0e+07 by the vector, so I used expand(B). It gives the following error Check for missing argument or incorrect argument data type in call to function 'expand'. How can I expand that expression anyway?

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Answer 1

Ayush 2023-7-16

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Hi @Priyanshu,

The expand function in MATLAB is used to expand and simplify symbolic expressions. However, in your case, you have a numeric vector B obtained from sym2poly, which means it contains numeric coefficients rather than symbolic expressions.

To perform the multiplication of the entire vector B by 1.0e+07, you don't need to use expand. You can simply multiply the vector by the scalar value directly.

B = [0.0000, 0.0003, 0.0103, 2.5110, 2.6503, -0.0500];

multiplied_B = 1.0e+07 * B;

So, B is your numeric vector, and multiplied_B will store the result of multiplying each element of B by 1.0e+07.

Note that there is no need to use expand in this case since you are dealing with numeric values rather than symbolic expressions.

Hope it helps!